Monday, July 9, 2012

When buying a sleeping mat, most people shop around a bit
and compare the different brands and models available. Important points such as
price, quality, comfort, ease of use, reliability, compressibility and warmth all
enter into the equation. But it's that last one, warmth, that's a bit sticky.
With all the other parameters it's pretty straightforward to compare mats.
Price and quality go together and info about comfort, ease of use, reliability,
and compressibility can all be culled from online reviews, in-store poking and prodding, and manufacturer
websites. But this warmth rating, R-value, isn't as easy to accurately verify across
brands and deserves an explanation, so we thought we'd clarify a few points.

R-value. Huh?

First, R-value is a measure of thermal resistance and is
most commonly associated with the construction industry. When you buy
insulation for your house, it's efficiency has been tested and is expressed
with a number, it's R-value. This allows you to compare insulation easily.
Because it's resistance to heat
transfer that's being measured, the higher the number, the more efficient it is
at retaining heat. Without getting
into the specifics (R =DT/QA),suffice
it to say that R-value is a useful way to compare the insulation efficiency of
different materials.

Ten years ago, Exped unveiled the patented DownMat. It was
revolutionary in many ways (down insulation, 7cm thick and super comfortable,
stuff sack inflated) and at that time Exped introduced R-value to sleeping
mats. It makes perfect sense to express warmth in this scientifically accurate
way.

Independent testing

So, as we just said, R-value is, theoretically, a good way
to compare insulation. What? Theoretically? It sounds like double speak. Sorry.
But here's why we say "theoretically." Like so many measurements used
by various industries (and customers!), the usefulness of the number is based
upon whether it can be readily compared across brands. Our mats are
independently tested by EMPA, the Swiss Federal Laboratories for Materials
Testing and Research. In other words, the R-value we state on our mats does not
originate from some over-zealous sales guy. Rather, it is arrived at by a
standard R-value test conducted by a neutral party. Being a Swiss company, we
are naturally big fans of tests like this and would love to see standardized
tests used by all mat manufacturers. Our industry is not there yet, but the
topic is being discussed, and that's a start. But certainly, within the Exped
line, you can compare mats accurately.

Exped mats offer a wide range of R-values and there is a mat
for every need. The following list shows the R-values of our mat line, low to
high:

·All AirMats 0.7

·MultiMat 1.2

·SynMat UL 7 3.1

·SynMat Basic 7.5 4.0

·SynMat 7 4.9

·ComfortFoam 7 4.9

·DownMat 7 5.9

·DownMat UL 7 5.9

·SynMat 9 6.0

·SIM Comfort 7.5 6.4

·DownMat 9 8.0

·SIM Comfort 10 9.5

·MegaMat 10 9.5

R-value and warmth

The whole idea of expressing mat warmth with an R-value is
to make buying a mat easier. Remember, the higher the number, the warmer the
mat. But not every situation requires the very warmest mat; there's a big
difference in nighttime temperatures between Florida and Alberta. Very warm
summer nights often require little or no insulation (Exped AirMat). On the
other hand, anyone doing any sort of snow camping will always be happy with a
warm mat. And as always, cold sleepers should always look for the warmest mat
they can afford. But in the end, most folks are best served by choosing a mat
for the coldest sleeping environments to be encountered and regulating their
sleep temperature by venting the sleeping bag in warmer weather. An alternative
to this is to use a lighter sleeping bag in warmer conditions, thereby reducing
pack weight and bulk.

Here's another thing to consider. The warmer the mat (higher
R-value) you use the more impressed you will be with your old sleeping bag. You
know, the one that's rated to 20°
F. but never seems warm enough below 32°F.
We've come to understand this not just from our personal experience, but from
countless emails and phone calls from our customers who report it to us. It
turns out that most of the heat loss you suffer during the night is going into
the cold, hard ground - not through your sleeping bag into the atmosphere. By
improving your ground insulation you will be substantially warmer and you'll
like your sleeping bag again!

So R-value can be very helpful when buying a sleeping mat.
Just remember that not all measurements are created equally.

ExpedLife.com

Welcome to ExpedLife.com, official blog of Exped/Seattle. We are the USA subsidiary of Exped AG in Switzerland, makers of the very best tents, sleeping bags, sleeping mats, trekking poles, and other outdoor gear. You will find updates here about our products and the people who design, build, and use them. And take note: we are a fun loving bunch - we try not to take ourselves too seriously. After all, isn't that why we all go out into the wilds, to have fun?

Exped was founded in 1983 as a distributor of outdoor brands in Europe. Since 1997, the Exped team has designed and built the highest quality specialized gear for the active outdoor enthusiast. This equipment is designed for adventurous users across a wide range of outdoor activities, from mountaineering and backpacking to backcountry skiing, paddling, car camping and trekking . Exped means expedition equipment, and through ingenious simplicity and innovation Exped delivers the maximum outdoor experience with minimal means. Exped is based in Zurich, Switzerland and Seattle, USA.